羟基磷灰石/氧化锆复合涂层热稳定性和结合强度的研究

Thermal Stability and Bonding Strength of Hydroxyapatite/zirconia Composite Coatings

为了提高羟基磷灰石(hydroxyapatite,HA)涂层的结合强度,采用水热电沉积法在HA涂层中引入第二相颗粒氧化锆(ZrO2)制备HA/ZrO2复合涂层,研究了ZrO2晶型对涂层表面形貌、相组成、热稳定性和涂层结合强度的影响。实验结果表明,ZrO2的复合减小了HA晶体尺寸,但不影响HA水热电沉积的机理;1200℃热处理后,HA分解生成的CaO和ZrO2形成固溶体,使单斜晶型(m-ZrO2)和四方晶型(t-ZrO2)的ZrO2转变为立方晶型的的ZrO2(c-ZrO2),并促进HA的完全分解;HA/ZrO2复合涂层的结合强度明显高于纯HA涂层的结合强度,且随涂层中ZrO2含量增大和热处理温度的升高而增大。1000℃热处理后,HA/ZrO2复合涂层既有较高的结合强度,又可获得对骨生长有利的HA+β-Ca3(PO4)2(β-TCP)双相结构。

Hydroxyapatite(HA)/zirconia(ZrO2) composite coatings were prepared by hydrothermal electrodeposition method through the introduction of ZrO2 particle as the second phase particle in the HA coating to improve the bonding strength of the coatings. The effect of ZrO2 crystal phase was studied on the surface morphologies, phase composition, thermal stability and the bonding strength of the coatings. The results show that the addition of ZrO2 reduces the HA crystal size, but does not change the mechanism of hydrothermal electrodeposition of HA. After being heated at 1200 degrees C for 2 h, monoclinie phase ZrO2 and tetragonal phase ZrO2 tend to react with the released CaO to form cubic zirconia, meanwhile this reaction promotes the complete decomposition of HA stable into more alpha-TCP phase. The bonding strength of HA/ZrO2 Composite coatings were higher than pure HA coatings, and the strength increased with the content of ZrO2 in the composite coatings and the heating temperature. After being heated at 1000 degrees C, HA/ZrO2 composite coatings would have higher bonding strength, and would form a biphase of HA+beta-Ca-3(PO4)(2)(beta-TCP) beneficial to bone growth.